1. Field of the Invention
The invention relates to Al-Ta alloy films and somewhat more particularly to highly temperature stable Al-Ta alloy films on non-conductive substrates for various electronic components, such as thin-film circuits, discrete resistors, capacitors, etc.
2. Prior Art
In tantalum thin-film technology, .beta. -tantalum films are generally employed for capacitors while tantalum nitride films and/or tantalum oxide nitride films are usually employed for resistors.
It is known (German Auslegeschrift No. 1,590,786) to use Ta-Al alloys which have a low Al content of about 3 to 20 atomic % as thin-film material for electronic components in micro-miniaturized circuits. Such low Al, tantalum alloys have a form similar to .beta. -tantalum crystals, which exhibit an undesirably high negative temperature coefficient of electric resistance. Furthermore, experience has shown that the stability of this low Al tantalum alloy and thus its utility for thin-layer cicuits only partially lives up to the claims therefor.
It is also known (German Auslegeschrift No. 1,925,194) to employ Ta-Al alloys which have an Al content of 25 to 60 atomic % Al as metal film resistors. However, apart from a somewhat improved stability in comparison to conventional tantalum nitride resistors, the resistors containing this Ta-Al alloy do not possess any special properties.